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ffmpeg/libavcodec/h263dec.c

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/*
* H263 decoder
* Copyright (c) 2001 Fabrice Bellard.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
//#define DEBUG
//#define PRINT_FRAME_TIME
#ifdef PRINT_FRAME_TIME
static inline long long rdtsc()
{
long long l;
asm volatile( "rdtsc\n\t"
: "=A" (l)
);
// printf("%d\n", int(l/1000));
return l;
}
#endif
static int h263_decode_init(AVCodecContext *avctx)
{
MpegEncContext *s = avctx->priv_data;
s->avctx = avctx;
s->out_format = FMT_H263;
s->width = avctx->width;
s->height = avctx->height;
s->workaround_bugs= avctx->workaround_bugs;
/* select sub codec */
switch(avctx->codec->id) {
case CODEC_ID_H263:
s->gob_number = 0;
s->first_slice_line = 0;
break;
case CODEC_ID_MPEG4:
s->time_increment_bits = 4; /* default value for broken headers */
s->h263_pred = 1;
s->has_b_frames = 1; //default, might be overriden in the vol header during header parsing
break;
case CODEC_ID_MSMPEG4V1:
s->h263_msmpeg4 = 1;
s->h263_pred = 1;
s->msmpeg4_version=1;
break;
case CODEC_ID_MSMPEG4V2:
s->h263_msmpeg4 = 1;
s->h263_pred = 1;
s->msmpeg4_version=2;
break;
case CODEC_ID_MSMPEG4V3:
s->h263_msmpeg4 = 1;
s->h263_pred = 1;
s->msmpeg4_version=3;
break;
case CODEC_ID_WMV1:
s->h263_msmpeg4 = 1;
s->h263_pred = 1;
s->msmpeg4_version=4;
break;
case CODEC_ID_H263I:
s->h263_intel = 1;
break;
default:
return -1;
}
s->codec_id= avctx->codec->id;
avctx->mbskip_table= s->mbskip_table;
/* for h263, we allocate the images after having read the header */
if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
if (MPV_common_init(s) < 0)
return -1;
if (s->h263_msmpeg4)
msmpeg4_decode_init_vlc(s);
else
h263_decode_init_vlc(s);
return 0;
}
static int h263_decode_end(AVCodecContext *avctx)
{
MpegEncContext *s = avctx->priv_data;
MPV_common_end(s);
return 0;
}
static int h263_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
UINT8 *buf, int buf_size)
{
MpegEncContext *s = avctx->priv_data;
int ret;
AVPicture *pict = data;
#ifdef PRINT_FRAME_TIME
uint64_t time= rdtsc();
#endif
#ifdef DEBUG
printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
#endif
s->hurry_up= avctx->hurry_up;
s->error_resilience= avctx->error_resilience;
s->workaround_bugs= avctx->workaround_bugs;
/* no supplementary picture */
if (buf_size == 0) {
*data_size = 0;
return 0;
}
if(s->bitstream_buffer_size && buf_size<20){ //divx 5.01+ frame reorder
init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size);
}else
init_get_bits(&s->gb, buf, buf_size);
s->bitstream_buffer_size=0;
/* let's go :-) */
if (s->h263_msmpeg4) {
ret = msmpeg4_decode_picture_header(s);
} else if (s->h263_pred) {
ret = mpeg4_decode_picture_header(s);
s->has_b_frames= !s->low_delay;
} else if (s->h263_intel) {
ret = intel_h263_decode_picture_header(s);
} else {
ret = h263_decode_picture_header(s);
}
/* After H263 & mpeg4 header decode we have the height, width,*/
/* and other parameters. So then we could init the picture */
/* FIXME: By the way H263 decoder is evolving it should have */
/* an H263EncContext */
if (!s->context_initialized) {
avctx->width = s->width;
avctx->height = s->height;
avctx->aspect_ratio_info= s->aspect_ratio_info;
if (MPV_common_init(s) < 0)
return -1;
} else if (s->width != avctx->width || s->height != avctx->height) {
/* H.263 could change picture size any time */
MPV_common_end(s);
if (MPV_common_init(s) < 0)
return -1;
}
if(ret==FRAME_SKIPED) return 0;
/* skip if the header was thrashed */
if (ret < 0)
return -1;
/* skip b frames if we dont have reference frames */
if(s->num_available_buffers<2 && s->pict_type==B_TYPE) return 0;
/* skip b frames if we are in a hurry */
if(s->hurry_up && s->pict_type==B_TYPE) return 0;
if(s->next_p_frame_damaged){
if(s->pict_type==B_TYPE)
return 0;
else
s->next_p_frame_damaged=0;
}
MPV_frame_start(s);
#ifdef DEBUG
printf("qscale=%d\n", s->qscale);
#endif
/* init resync/ error resilience specific variables */
s->next_resync_qscale= s->qscale;
s->next_resync_gb= s->gb;
if(s->resync_marker) s->mb_num_left= 0;
else s->mb_num_left= s->mb_num;
/* decode each macroblock */
s->block_wrap[0]=
s->block_wrap[1]=
s->block_wrap[2]=
s->block_wrap[3]= s->mb_width*2 + 2;
s->block_wrap[4]=
s->block_wrap[5]= s->mb_width + 2;
for(s->mb_y=0; s->mb_y < s->mb_height; s->mb_y++) {
/* Check for GOB headers on H.263 */
/* FIXME: In the future H.263+ will have intra prediction */
/* and we are gonna need another way to detect MPEG4 */
if (s->mb_y && !s->h263_pred) {
s->first_slice_line = h263_decode_gob_header(s);
}
if(s->msmpeg4_version==1){
s->last_dc[0]=
s->last_dc[1]=
s->last_dc[2]= 128;
}
s->block_index[0]= s->block_wrap[0]*(s->mb_y*2 + 1) - 1;
s->block_index[1]= s->block_wrap[0]*(s->mb_y*2 + 1);
s->block_index[2]= s->block_wrap[0]*(s->mb_y*2 + 2) - 1;
s->block_index[3]= s->block_wrap[0]*(s->mb_y*2 + 2);
s->block_index[4]= s->block_wrap[4]*(s->mb_y + 1) + s->block_wrap[0]*(s->mb_height*2 + 2);
s->block_index[5]= s->block_wrap[4]*(s->mb_y + 1 + s->mb_height + 2) + s->block_wrap[0]*(s->mb_height*2 + 2);
for(s->mb_x=0; s->mb_x < s->mb_width; s->mb_x++) {
s->block_index[0]+=2;
s->block_index[1]+=2;
s->block_index[2]+=2;
s->block_index[3]+=2;
s->block_index[4]++;
s->block_index[5]++;
#ifdef DEBUG
printf("**mb x=%d y=%d\n", s->mb_x, s->mb_y);
#endif
if(s->resync_marker){
if(s->mb_num_left<=0){
/* except the first block */
if(s->mb_x!=0 || s->mb_y!=0){
/* did we miss the next resync marker without noticing an error yet */
if(((get_bits_count(&s->gb)+8)&(~7)) != s->next_resync_pos && s->decoding_error==0){
fprintf(stderr, "slice end missmatch x:%d y:%d %d %d\n",
s->mb_x, s->mb_y, get_bits_count(&s->gb), s->next_resync_pos);
ff_conceal_past_errors(s, 1);
}
}
s->qscale= s->next_resync_qscale;
s->gb= s->next_resync_gb;
s->resync_mb_x= s->mb_x; //we know that the marker is here cuz mb_num_left was the distance to it
s->resync_mb_y= s->mb_y;
s->first_slice_line=1;
if(s->codec_id==CODEC_ID_MPEG4){
ff_mpeg4_clean_buffers(s);
ff_mpeg4_resync(s);
}
}
if( s->resync_mb_x==s->mb_x
&& s->resync_mb_y==s->mb_y && s->decoding_error!=0){
fprintf(stderr, "resynced at %d %d\n", s->mb_x, s->mb_y);
s->decoding_error= 0;
}
}
//fprintf(stderr,"\nFrame: %d\tMB: %d",avctx->frame_number, (s->mb_y * s->mb_width) + s->mb_x);
/* DCT & quantize */
if (s->h263_pred && !(s->msmpeg4_version==1 || s->msmpeg4_version==2)) {
/* old ffmpeg encoded msmpeg4v3 workaround */
if(s->workaround_bugs==1 && s->msmpeg4_version==3)
ff_old_msmpeg4_dc_scale(s);
else
h263_dc_scale(s);
} else {
/* default quantization values */
s->y_dc_scale = 8;
s->c_dc_scale = 8;
}
if(s->decoding_error!=DECODING_DESYNC){
int last_error= s->decoding_error;
clear_blocks(s->block[0]);
s->mv_dir = MV_DIR_FORWARD;
s->mv_type = MV_TYPE_16X16;
if (s->h263_msmpeg4) {
if (msmpeg4_decode_mb(s, s->block) < 0) {
fprintf(stderr,"Error at MB: %d\n", (s->mb_y * s->mb_width) + s->mb_x);
s->decoding_error=DECODING_DESYNC;
}
} else {
if (h263_decode_mb(s, s->block) < 0) {
fprintf(stderr,"Error at MB: %d\n", (s->mb_y * s->mb_width) + s->mb_x);
s->decoding_error=DECODING_DESYNC;
}
}
if(s->decoding_error!=last_error){
ff_conceal_past_errors(s, 0);
}
}
/* conceal errors */
if( s->decoding_error==DECODING_DESYNC
|| (s->decoding_error==DECODING_ACDC_LOST && s->mb_intra)){
s->mv_dir = MV_DIR_FORWARD;
s->mv_type = MV_TYPE_16X16;
s->mb_skiped=0;
s->mb_intra=0;
s->mv[0][0][0]=0; //FIXME this is not optimal
s->mv[0][0][1]=0;
clear_blocks(s->block[0]);
}else if(s->decoding_error && !s->mb_intra){
clear_blocks(s->block[0]);
}
//FIXME remove AC for intra
MPV_decode_mb(s, s->block);
s->mb_num_left--;
}
if ( avctx->draw_horiz_band
&& (s->num_available_buffers>=1 || (!s->has_b_frames)) ) {
UINT8 *src_ptr[3];
int y, h, offset;
y = s->mb_y * 16;
h = s->height - y;
if (h > 16)
h = 16;
offset = y * s->linesize;
if(s->pict_type==B_TYPE || (!s->has_b_frames)){
src_ptr[0] = s->current_picture[0] + offset;
src_ptr[1] = s->current_picture[1] + (offset >> 2);
src_ptr[2] = s->current_picture[2] + (offset >> 2);
} else {
src_ptr[0] = s->last_picture[0] + offset;
src_ptr[1] = s->last_picture[1] + (offset >> 2);
src_ptr[2] = s->last_picture[2] + (offset >> 2);
}
avctx->draw_horiz_band(avctx, src_ptr, s->linesize,
y, s->width, h);
}
}
if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
if(msmpeg4_decode_ext_header(s, buf_size) < 0) return -1;
/* divx 5.01+ bistream reorder stuff */
if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0){
int current_pos= get_bits_count(&s->gb)>>3;
if( buf_size - current_pos > 5
&& buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
int i;
int startcode_found=0;
for(i=current_pos; i<buf_size; i++){
if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
startcode_found=1;
break;
}
}
if(startcode_found){
memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
s->bitstream_buffer_size= buf_size - current_pos;
}
}
}
if(s->bitstream_buffer_size==0 && s->error_resilience>0){
int left= s->gb.size*8 - get_bits_count(&s->gb);
int max_extra=8;
if(s->codec_id==CODEC_ID_MPEG4) max_extra+=32;
if(left>max_extra){
fprintf(stderr, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
if(s->decoding_error==0)
ff_conceal_past_errors(s, 1);
}
if(left<0){
fprintf(stderr, "overreading %d bits\n", -left);
if(s->decoding_error==0)
ff_conceal_past_errors(s, 1);
}
}
MPV_frame_end(s);
#if 0 //dirty show MVs, we should export the MV tables and write a filter to show them
{
int mb_y;
s->has_b_frames=1;
for(mb_y=0; mb_y<s->mb_height; mb_y++){
int mb_x;
int y= mb_y*16 + 8;
for(mb_x=0; mb_x<s->mb_width; mb_x++){
int x= mb_x*16 + 8;
uint8_t *ptr= s->last_picture[0];
int xy= 1 + mb_x*2 + (mb_y*2 + 1)*(s->mb_width*2 + 2);
int mx= (s->motion_val[xy][0]>>1) + x;
int my= (s->motion_val[xy][1]>>1) + y;
int i;
int max;
if(mx<0) mx=0;
if(my<0) my=0;
if(mx>=s->width) mx= s->width -1;
if(my>=s->height) my= s->height-1;
max= ABS(mx-x);
if(ABS(my-y) > max) max= ABS(my-y);
/* the ugliest linedrawing routine ... */
for(i=0; i<max; i++){
int x1= x + (mx-x)*i/max;
int y1= y + (my-y)*i/max;
ptr[y1*s->linesize + x1]+=100;
}
ptr[y*s->linesize + x]+=100;
s->mbskip_table[mb_x + mb_y*s->mb_width]=0;
}
}
}
#endif
if(s->pict_type==B_TYPE || (!s->has_b_frames)){
pict->data[0] = s->current_picture[0];
pict->data[1] = s->current_picture[1];
pict->data[2] = s->current_picture[2];
} else {
pict->data[0] = s->last_picture[0];
pict->data[1] = s->last_picture[1];
pict->data[2] = s->last_picture[2];
}
pict->linesize[0] = s->linesize;
pict->linesize[1] = s->linesize / 2;
pict->linesize[2] = s->linesize / 2;
avctx->quality = s->qscale;
/* Return the Picture timestamp as the frame number */
/* we substract 1 because it is added on utils.c */
avctx->frame_number = s->picture_number - 1;
/* dont output the last pic after seeking
note we allready added +1 for the current pix in MPV_frame_end(s) */
if(s->num_available_buffers>=2 || (!s->has_b_frames))
*data_size = sizeof(AVPicture);
#ifdef PRINT_FRAME_TIME
printf("%Ld\n", rdtsc()-time);
#endif
return buf_size;
}
AVCodec mpeg4_decoder = {
"mpeg4",
CODEC_TYPE_VIDEO,
CODEC_ID_MPEG4,
sizeof(MpegEncContext),
h263_decode_init,
NULL,
h263_decode_end,
h263_decode_frame,
CODEC_CAP_DRAW_HORIZ_BAND,
};
AVCodec h263_decoder = {
"h263",
CODEC_TYPE_VIDEO,
CODEC_ID_H263,
sizeof(MpegEncContext),
h263_decode_init,
NULL,
h263_decode_end,
h263_decode_frame,
CODEC_CAP_DRAW_HORIZ_BAND,
};
AVCodec msmpeg4v1_decoder = {
"msmpeg4v1",
CODEC_TYPE_VIDEO,
CODEC_ID_MSMPEG4V1,
sizeof(MpegEncContext),
h263_decode_init,
NULL,
h263_decode_end,
h263_decode_frame,
CODEC_CAP_DRAW_HORIZ_BAND,
};
AVCodec msmpeg4v2_decoder = {
"msmpeg4v2",
CODEC_TYPE_VIDEO,
CODEC_ID_MSMPEG4V2,
sizeof(MpegEncContext),
h263_decode_init,
NULL,
h263_decode_end,
h263_decode_frame,
CODEC_CAP_DRAW_HORIZ_BAND,
};
AVCodec msmpeg4v3_decoder = {
"msmpeg4",
CODEC_TYPE_VIDEO,
CODEC_ID_MSMPEG4V3,
sizeof(MpegEncContext),
h263_decode_init,
NULL,
h263_decode_end,
h263_decode_frame,
CODEC_CAP_DRAW_HORIZ_BAND,
};
AVCodec wmv1_decoder = {
"wmv1",
CODEC_TYPE_VIDEO,
CODEC_ID_WMV1,
sizeof(MpegEncContext),
h263_decode_init,
NULL,
h263_decode_end,
h263_decode_frame,
CODEC_CAP_DRAW_HORIZ_BAND,
};
AVCodec h263i_decoder = {
"h263i",
CODEC_TYPE_VIDEO,
CODEC_ID_H263I,
sizeof(MpegEncContext),
h263_decode_init,
NULL,
h263_decode_end,
h263_decode_frame,
CODEC_CAP_DRAW_HORIZ_BAND,
};
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